1. Field of the Invention
The present invention relates to a shadow mask, a film forming system using a shadow mask, and a method of manufacturing a display device.
2. Description of the Related Art
Recent years, a thin display device using a semiconductor element has been put into practical use. When forming an organic layer of an organic EL element or an electrode of a liquid crystal display device by a vapor deposition or sputtering, a shadow mask on which many fine slits are aligned in parallel is used. A shadow mask is also referred to as a vapor deposition mask or a metal mask. For example, a planar mask where a thin mask foil 404 having an opening 402 that is in accordance with a shape of a film to be formed is welded to a frame 400 made of metal as illustrated in FIG. 4 is used. However, as a development of a shadow mask progresses, a development of a shadow mask that is not in a planar form is also proceeded.
For example, Japanese Unexamined Patent Application Publication No. 2008-226689 discloses performing a pattern film formation on a substrate by bringing a roll-shaped mask made of metal into close contact with a substrate that is being conveyed, rotating the mask in synchronization with the conveyance of the substrate, and at the same time providing a sputtering source inside the roll.
Further, WO 2013/145800 A1 discloses that a cylinder-shaped mask retaining device attracts a sheet-shaped mask substrate using an electromagnet and an exposure is performed using the mask substrate.